Protected insulated heating element for electric percolators



N. E. LOOMIS Dec. 1, 1959 PROTECTED INSULATED HEATING ELEMENT FORELECTRIC PERCOLATORS Filed NOV. 21, 1958 2 Sheets-Sheet 1 ATTORNEY N. E.LOOMIS PROTECTED INSULATED HEATING ELEMENT FOR ELECTRIC PERCOLATORSFiled Nov. 21, 1958 2 Sheets-Sheet 2 FIG. 4.

United States Patent PROTECTED INSULATED HEATING ELEMENT FOR ELECTRICPERCOLATORS Nelson E. Loomis, Winsted, Conn., assignor to Son-ChiefElectrics, Inc., Winsted, Conn., a corporation of ConnecticutApplication November 21, 1958, Serial No. 775,646 -1 Claim. (Cl. 219-44)This invention relates to an improvement in percolators which enablesthe same to be immersed, or otherwise washed or sanitized, withoutdanger of damaging the electrical heating unit and its thermostat.

One of the objects of the invention is to thoroughly and adequatelywaterproof all of the live electrical parts such as wires, terminals,connections and the like by covering the same individually with aninsulation material which is initially in a more or less fluid state bydipping, spraying or otherwise placing the insulation on the electricalparts so that they will be impervious to water and still stand the heatnecessary in a percolator without disintegrating. Thus, the electricalelements are completely protected and may be freely cleansed without thehazard of impairing their conductivity and materially adding. to thelongevity of the device embodying the invention.

Another object of the invention is to provide a percolatorhaving itselectrical heating unit, as well as its thermostat, completely encasedor enveloped in a waterproof and heat resistant medium which may bemolded thereabout as a block and which, upon hardening or setting,becomes a permanent part of the unit.

With the above and other objects in view, which will more readily appearas the nature of the invention is better understood, the inventionconsists in the novel construction, combination and arrangement ofparts,

hereinafter more fully described, illustrated and claimed.

A preferred and practical embodiment of the invention is shown intheaccompanying drawings, in which:

Figure 1 is a side elevation of a colfee-maker.

Fig. 2 is a bottom perspective view of the appliance shown in Figure 1with the supporting base removed to illustrate the electrical unitencased in insulating material in accordance with one form of thepresent invention.

Figure 3 is a side elevation, partly in section, taken on the line 3-3of Figure 2.

Figure 4 is a side elevation, partly in section, of another form of theinvention showing the heating element and its wiring connections, withthe waterproofing compound applied by spraying or dipping.

Figure 5 is a bottom perspective view of the percolator shown in Figure4.

Similar reference characters designate corresponding parts throughoutthe several figures of the drawing.

As shown in the drawings, the percolator includes a receptacle A havinga base B which contains an electrical thermostatically controlledheating unit designated generally as C.

In the form of the invention shown in Figures 1 to 3, the electricalheating unit includes a shell 1 housing the electrical resistanceelements proper, which are normally concealed therein and which may havea threaded neck portion 2 for insertion into the opening 3 in the bottomwall 4 of the percolator. The neck portion 2 may be externally threadedto receive a gasket 5 and a lock nut 6 to securely .hold the electricalheating elements to the bottom 4 of the appliance.

It will, of course, be understood that the electrical heating unit C isprovided with externally accessible plug elements 7 which enable it tobe connected with any conventional outlet cord. These elements may becarried by the shell 1 as in Figures 1 to 3, for example, and which isin the form of a band shaped to encase the heating element. This shellconstitutes a mold for receiving insulating material M in its fiowablestate. Preferably an adhesive type of fiowable insulating material isused, such as Silastic rubber, or polyester or epoxy resins. Thereforeit will be understood that when the shell is filled with the fiowablematerial, it not only completely encases and protects the electricalheating element C as well as the connections to the terminals 7, but atthe same time contacts the outer face of the bottom wall 4. In otherwords, when the fiowable insulating material M hardens or sets, it sealsall contact between the electrical unit and the bottom wall 4 of thepercolator and at the same time permeates and envelops every nook andcranny about the electrical resistance unit 1 to render it impervious towater or moisture.

Preferably the insulating material M is filled to the outer-edge 1a ofthe shell or band so as to provide an external surface M whichconstitutes a complete wall surface for the portion of the shell lyingopposite the bottom wall 4.

In the modified form of the invention shown in Figures 4 and 5, wherethe shell or mold 1 is to be dispensed with, the heating unit C and theelectrical connections, including the thermostat, are encased with thewaterproof insulating material by the spraying, dipping or otherappropriate method of encasement or envelopment. Since the shell 1 isnot used in this form of the invention, the terminals 7 are supported bymeans of a bracket 8 independently secured to the bottom wall 4 of thepercolator.

It is also within the scope of my invention that instead of filling theshell with the fiowable material, a comparatively thin layer of thematerial can be applied to the bottom wall 4 within the shell 1, also tothe inner side wall of the shell, and the open end of the shell can besealed off with a cover member formed of the same material just prior toits reaching its set condition. There would thus be formed a waterproofskin surrounding and protecting the heating element.

It will now be seen that the foregoing construction provides a safetyinsulated and waterproofed electrical unit which is not affected byconditions such as extreme heat or by immersion in cleansing fluids.

I claim:

In an electric percolator intended to be immersed in a cleansing fluidand having a bottom wall with a centrally located opening therein, aheating element secured to said bottom wall through said opening, asubstantially U-shaped bracket also secured to said bottom wall adjacentsaid heating element, a thermostat and terminal members each carried bysaid bracket and wires connecting said heating element with saidthermostat and terminals, a heat and moisture resistant coating of epoxyresin encasing said heating element, thermostat and wiring, and a basemember secured to the percolator side walls and enclosing said heatingelement and related parts.

References Cited in the file of this patent UNITED STATES PATENTS1,442,910 Steinhardt Jan. 23, 1923 1,655,720 Ziola Jan. 10, 19282,164,813 Gunther July 4, 1939 2,396,087 Cox et al. Mar. 5, 19462,682,595 Rubenstein June 29, 1954 2,706,742 Ehlers Apr. 19, 19552,814,703 Martin Nov. 26, 1957 2,860,227 Fox Nov. 11, 1958

